Computer systems are constantly improving in terms of speed, reliability, and processing capability. As is known in the art, computer systems which process and store large amounts of data typically include a one or more processors in communication with a shared data storage system in which the data is stored. The data storage system may include one or more storage devices, usually of a fairly robust nature and useful for storage spanning various temporal requirements, e.g., disk drives. The one or more processors perform their respective operations using the storage system. Mass storage systems (MSS) typically include an array of a plurality of disks with on-board intelligent and communications electronics and software for making the data on the disks available.
Companies that sell data storage systems and the like are very concerned with providing customers with an efficient data storage solution that minimizes cost while meeting customer data storage needs. It would be beneficial for such companies to have a way for reducing the complexity of implementing data storage.
Storage arrays are typically used to provide storage space for one or more computer file systems, databases, applications, and the like. For this and other reasons, it is common for storage arrays to be logically partitioned into chunks of storage space, called logical units, or LUs. A logical unit may be a logical entity provided by a storage system for accessing data stored in the storage system. In particular, to enable initiators to send requests to a data storage system, the data storage system exposes one or more LUs to which commands are issued. A logical unit number (LUN) may be a logical unit number for identifying a logical unit. A logical unit also may be referred to herein interchangeably as a logical volume or a logical device. This allows a unified storage array to appear as a collection of separate file systems, network drives, and/or Logical Units. The Storage Array keeps track of the logical unit to physical unit association in a map. The map associates a host logical unit address with a physical device address. A LUN may be a logical unit number which is an identifier for a Logical Unit. Summary Example embodiments of the present invention relate to a method, a system, and a computer program product for creating a cascaded storage group. The method includes receiving a request to group a first set of logical units (LUs) (also referred to herein as logical volumes or logical devices, as discussed below) in a new storage group and determining whether a second set of LUs/logical volumes grouped in an existing storage group is a subset of the first set of LUs/logical volumes. The method also includes creating a cascaded storage group according to the determination.